The invention relates to a coupling device and apparatus in the drive mechanism for a movable panel of an open roof construction for a vehicle, intended to alternately couple and uncouple [a driving part an]a driven part with respect to a driving part and to alternately lock and unlock the driven part with respect to a stationary part fixedly mounted to the roof.
In such a device, a coupling member is connected to the driven part and is movable in direction transverse to the movement of the driven part. The coupling member is movable between a coupling position in which it couples the driven part to the driving part, and a locking position in which it locks the driven part with respect to the stationary part.
Such a coupling device is known from the German Pat. specification No. 3.146.698. In that patent specification, the coupling member consists of a slide displaceable in transverse direction. As guide element the coupling member has a guide slot inclining in transverse direction and opening at its front side, the guide slot being able to cooperate with a guide cam formed on the stationary guide. Between the coupling member and the driven part there is provided a leaf spring loading the coupling member in a direction to its coupling position.
This leaf spring is disadvantageous. It causes additional friction in the locking position of the coupling member, because the leaf spring loads the coupling member against the driving part. Furthermore, the coupling device is not positively held in its coupling position; but can be accidentally displaced from that position against the force of the spring.
It is an object of the present invention to provide a coupling apparatus of the type mentioned above, but without the disadvantages of this prior art.
For this purpose the stationary part of the coupling apparatus of the present invention includes a pair of parallel, relatively straight guide rails fixedly mounted on either side of the roof opening and a counter part or latch plate fixedly mounted with respect to the roof and the guide rails. The coupling member is in engagement with this latch plate when it is in the locking position. The latch plate of the stationary part is provided with a latch plate guide element and the coupling member is provided with a cooperating latch guide element, each situated to cooperate with the other to bring the coupling member and latch plate into and out of engagement with each other. The coupling member has cam guide elements, and the driving part has cooperating cam guide elements, wherein the guide elements of the stationary part, the driving part and the coupling member are arranged and constructed such that in any position the coupling member is positively guided and is positively retained against undesired displacements.
In this way there is no need for a spring in the coupling apparatus anymore, while the proper operation of the coupling device is ensured at all times since the guide elements prevent an undesired displacement of the coupling member in a positive way.
An advantageous embodiment of the coupling apparatus according to the invention is characterized in that the guide elements of the stationary part and the coupling member effect the first initial movement from the coupling position and the last return movement to the coupling position, wherein for each of these movements separate guide elements are provided, and the remaining movements of the coupling member are determined by the mutual interaction of the guide elements of the coupling member and the driving part.
By providing separate guide elements for the first initial movement from the coupling position and the last return movement to the coupling position it is possible to obtain a locked coupling position of the coupling member without loading the coupling member in sideways direction.
Preferably, the coupling member is connected to the driven part pivotable about a substantially vertical pivot axis to move between the coupling position and the locking position. Said pivoting movement of the coupling member between the coupling position and the locking position requires little force to be placed on the driving part, and there will not develop any torque causing friction during said pivoting movement.
Preferably, the coupling member is provided with a forwardly facing stop cam positioned radially outwardly from the pivot axis, and the stationary part is provided with a stop shoulder facing backwardly and lying in the path of the stop cam when the coupling member is in the coupling position.
The movement of the stop cam of the coupling member against the stop shoulder of the stationary part effects the first initial movement of the coupling member from the coupling position in a simple and facile manner.
The stationary part latch plate is provided with a locking recess. The coupling member is provided with a locking nose or latch which is able to engage into the locking recess.
Part of the rear wall of the latch plate locking recess is formed as a guiding surface inclined backwardly in the direction to the driven part. A guiding surface is also formed on the locking nose or latch of the coupling member. These two guiding surfaces cooperate with each other. By this cooperation of these guiding surfaces of the latch of the coupling member and the locking recess, the last return movement of the coupling member to the coupling position is achieved, whereby it is made possible to bring the coupling member into a stable retained position, from which the coupling member can only be displaced by the first initial movements of these guiding surfaces with respect to each other.
In a preferred embodiment of the invention, the driving part is provided with a guide slot whose side walls form the guide elements; and the coupling member includes a guide cam which serves as a guide element and which is in engagement with the guide slot of the driving part.
This engagement between these guide elements of the coupling member and the driving part causes the coupling member to be forcibly guided by the driving part as well as to be positively retained thereby.
As shown herein, the guide slot in the driving part is provided with a rear slot portion parallel to the direction of movement of the driving part, an intermediate slot portion inclining to said direction of movement, and a front slot portion substantially transverse to said direction of movement.
The rear slot portion of the guide slot in the driving part causes the retaining of the coupling member in the locking position, the inclined intermediate slot portion effectuates a part of the pivoting movement of the coupling member, and the substantially transverse front slot portion offers a stable coupling position to the coupling member.
Herein it is favorable that when in the coupling position of the coupling member, the line of connection between the point of engagement of the coupling member with the driving part and the point of engagement of the coupling member with the driven part extends substantially parallel to the direction of movement of the driving part. In this way, no torque will develop on the coupling member during the driving of the driven part by the driving part, so that no additional friction occurs and a light driving operation is possible.
Preferably, the driving part is provided with a backwardly facing stop shoulder, and the driven part is provided with a forwardly facing stop shoulder lying in the path of said backwardly facing stop shoulder of the driving part. Consequently, a simple and direct driving of the driven part takes place by the backward sliding movement of the driving part.
Advantageously, in the coupling position of the coupling member the latch thereof is laterally retained with play between a longitudinal edge of the driven part and a longitudinal edge of the stationary part. In this way the coupling member is fully retained in its coupling position.
The invention will hereafter be elucidated with reference to the drawing which shows an embodiment of the coupling apparatus according to the invention by way of example.